U.S. patent application number 17/292662 was filed with the patent office on 2022-01-06 for system and apparatus for preventing therapy unit contamination.
The applicant listed for this patent is KCI Licensing, Inc.. Invention is credited to Christopher Brian LOCKE, Benjamin Andrew PRATT.
Application Number | 20220001095 17/292662 |
Document ID | / |
Family ID | 1000005882270 |
Filed Date | 2022-01-06 |
United States Patent
Application |
20220001095 |
Kind Code |
A1 |
LOCKE; Christopher Brian ;
et al. |
January 6, 2022 |
System And Apparatus For Preventing Therapy Unit Contamination
Abstract
In some examples, provided is a fluid blockage device for use
with a reduced-pressure source for treating a tissue site with
reduced pressure. The fluid blockage device may be configured to
preclude fluid communication through a port fluidly coupled to the
reduced-pressure source when the fluid blockage device contacts a
liquid. Other devices, systems, and methods are disclosed.
Inventors: |
LOCKE; Christopher Brian;
(Bournemouth, GB) ; PRATT; Benjamin Andrew;
(Poole, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KCI Licensing, Inc. |
San Antonio |
TX |
US |
|
|
Family ID: |
1000005882270 |
Appl. No.: |
17/292662 |
Filed: |
October 21, 2019 |
PCT Filed: |
October 21, 2019 |
PCT NO: |
PCT/US2019/057137 |
371 Date: |
May 10, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62769487 |
Nov 19, 2018 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 1/90 20210501; A61M
1/784 20210501; A61F 13/0216 20130101 |
International
Class: |
A61M 1/00 20060101
A61M001/00; A61F 13/02 20060101 A61F013/02 |
Claims
1. A system for treating a tissue site, comprising: a dressing
configured to be positioned in contact with the tissue site; a
reduced-pressure source configured to be in fluid communication
with the dressing; and a canister assembly configured to be in
fluid communication between the dressing and the reduced-pressure
source, the canister assembly comprising: a fluid canister having
an internal volume configured to receive fluid from the tissue
site, a canister lid configured to provide a sealed enclosure
relative to the fluid canister, a fluid entry port configured to
provide fluid communication between the sealed enclosure and the
dressing, a reduced-pressure port including an inlet and an outlet
configured to provide fluid communication between the sealed
enclosure and the reduced-pressure source, and a fluid blockage
device configured to preclude fluid communication through the
reduced-pressure port when exposed to a liquid.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. The system of claim 1, wherein the fluid blockage device
comprises an absorbent material configured to swell when exposed to
the liquid.
8. The system of claim 1, wherein the fluid blockage device
comprises a secondary filter.
9. (canceled)
10. (canceled)
11. The system of claim 1, further comprising a primary filter
configured to be in fluid communication between the sealed
enclosure and the reduced-pressure source.
12. (canceled)
13. The system of claim 11, wherein the fluid blockage device is
configured to be positioned in fluid communication between the
primary filter and the reduced-pressure source.
14. The system of claim 11, wherein the fluid blockage device is
positioned in fluid communication between the primary filter and
the outlet of the reduced-pressure port.
15. The system of claim 11, wherein the primary filter comprises a
sintered, hydrophobic polymer.
16. (canceled)
17. The system of claim 11, wherein the reduced-pressure port
comprises an internal diameter and an external diameter, and
wherein the fluid blockage device is sized to fit within and to
engage the internal diameter of the reduced-pressure port and the
primary filter is sized to fit around the external diameter of the
reduced-pressure port.
18. The system of claim 11, wherein the fluid blockage device
comprises a tube having an external diameter sized to fit within
and to engage an internal diameter of the reduced-pressure port
between the inlet and the outlet, wherein the tube comprises an
internal lumen extending through opposing ends of the tube, and
wherein the tube is configured to swell when in direct contact with
the liquid such that the internal lumen is occluded and the
external diameter of the tube sealingly engages the
reduced-pressure port.
19. (canceled)
20. (canceled)
21. (canceled)
22. The system of claim 1, wherein the fluid blockage device
comprises a protective housing including a fluid aperture
configured to provide fluid communication between the
reduced-pressure port and the sealed enclosure until a liquid level
in the sealed enclosure occludes the fluid aperture.
23. The system of claim 22, wherein the protective housing is
configured to surround and to cover the reduced-pressure port.
24. (canceled)
25. (canceled)
26. The system of claim 22, wherein the protective housing is
coupled around the inlet of the reduced-pressure port.
27. The system of claim 22, wherein the reduced-pressure port
carries a primary filter in fluid communication between the sealed
enclosure and the reduced-pressure source, wherein the protective
housing comprises a base, a side-wall extending outward from and
around the base to form a chamber, and a chamber opening sized to
receive the reduced-pressure port and the primary filter within the
chamber.
28. The system of claim 27, wherein the fluid aperture is disposed
through the base of the protective housing at a maximum distance of
extension from the reduced-pressure port into the sealed
enclosure.
29. The system of claim 27, wherein the fluid aperture is biased
toward the side-wall of the protective housing.
30. (canceled)
31. (canceled)
32. (canceled)
33. The system of claim 1, further comprising: a carrier
comprising: a reduced-pressure port fitting configured to be
coupled in fluid communication with the reduced-pressure port, a
flared opening in fluid communication with the reduced-pressure
port fitting, the flared opening having a flared diameter larger
than a fitting diameter of the reduced-pressure port fitting, and
wherein the flared diameter of the flared opening is substantially
the same as an internal diameter of the fluid canister; and a
primary filter positioned at the flared opening of the carrier and
configured to be in fluid communication between the sealed
enclosure and the reduced-pressure port fitting; wherein the fluid
blockage device is configured to be positioned in fluid
communication between the reduced-pressure port fitting and the
primary filter, and wherein the fluid blockage device comprises an
absorbent material configured to swell when exposed to the
liquid.
34. A canister assembly for treating a tissue site with
reduced-pressure, comprising: a fluid canister having an internal
volume configured to receive fluid from the tissue site; a canister
lid configured to provide a sealed enclosure relative to the fluid
canister when the canister lid is sealingly engaged with the fluid
canister; a reduced-pressure port including an inlet and an outlet
configured to provide fluid communication with the sealed
enclosure, wherein the inlet is configured to face the sealed
enclosure and the outlet is configured to face outward from the
sealed enclosure; and a fluid blockage device configured to
preclude fluid communication through the reduced-pressure port when
exposed to a liquid.
35. (canceled)
36. The canister assembly of claim 34, wherein the fluid blockage
device comprises an absorbent material configured to swell when
exposed to the liquid.
37. The canister assembly of claim 34, wherein the reduced-pressure
port carries a primary filter at the inlet of the reduced-pressure
port, and wherein the fluid blockage device is positioned between
the inlet and the outlet of the reduced-pressure port.
38. The canister assembly of claim 37, wherein the fluid blockage
device is positioned in fluid communication between the primary
filter and the outlet of the reduced-pressure port.
39-42. (canceled)
Description
RELATED APPLICATIONS
[0001] This application is a National Phase of PCT/US2019/057137,
filed Oct. 21, 2019, which claims priority to U.S. Provisional
Patent Application No. 62/769,487, entitled "System and Apparatus
for Preventing Therapy Unit Contamination," filed Nov. 19, 2018,
which is incorporated herein by reference for all purposes.
TECHNICAL FIELD
[0002] The invention set forth in the appended claims relates
generally to tissue treatment systems, and more particularly, but
without limitation, to systems, apparatus, and methods configured
to prevent contamination of a therapy unit suitable for treating a
tissue site.
BACKGROUND
[0003] Clinical studies and practice have shown that reducing
pressure in proximity to a tissue site can augment and accelerate
growth of new tissue at the tissue site. The applications of this
phenomenon are numerous, but it has proven particularly
advantageous for treating wounds. Regardless of the etiology of a
wound, whether trauma, surgery, or another cause, proper care of
the wound is important to the outcome. Treatment of wounds or other
tissue with reduced pressure may be commonly referred to as
"negative-pressure therapy," but is also known by other names,
including "negative-pressure wound therapy," "reduced-pressure
therapy," "vacuum therapy," "vacuum-assisted closure," and "topical
negative-pressure," for example. Negative-pressure therapy may
provide a number of benefits, including migration of epithelial and
subcutaneous tissues, improved blood flow, and micro-deformation of
tissue at a wound site. Together, these benefits can increase
development of granulation tissue and reduce healing times.
[0004] There is also widespread acceptance that cleansing a tissue
site can be highly beneficial for new tissue growth. For example, a
wound or a cavity can be washed out with a liquid solution for
therapeutic purposes. These practices are commonly referred to as
"irrigation" and "lavage" respectively. "Instillation" is another
practice that generally refers to a process of slowly introducing
fluid to a tissue site and leaving the fluid for a prescribed
period of time before removing the fluid. For example, instillation
of topical treatment solutions over a wound bed can be combined
with negative-pressure therapy to further promote wound healing by
loosening soluble contaminants in a wound bed and removing
infectious material. As a result, soluble bacterial burden can be
decreased, contaminants removed, and the wound cleansed.
[0005] While the clinical benefits of negative-pressure therapy
and/or instillation therapy are widely known, improvements to
therapy systems, components, and processes may benefit healthcare
providers and patients.
BRIEF SUMMARY
[0006] New and useful systems, apparatuses, and methods for
treating a tissue site in a negative-pressure therapy environment
are set forth in the appended claims. Illustrative embodiments are
also provided to enable a person skilled in the art to make and use
the claimed subject matter.
[0007] In some example embodiments, a system for treating a tissue
site may include a dressing, a reduced-pressure source, and a
canister assembly. The dressing may be configured to be positioned
in contact with the tissue site. The reduced-pressure source may be
configured to be in fluid communication with the dressing. The
canister assembly may be configured to be in fluid communication
between the dressing and the reduced-pressure source. The canister
assembly may include a fluid canister, a canister lid, a fluid
entry port, a reduced-pressure port, and a fluid blockage device.
The fluid canister may have an internal volume configured to
receive fluid from the tissue site. The canister lid may be
configured to provide a sealed enclosure relative to the fluid
canister when the canister lid is sealingly engaged with the fluid
canister. The fluid entry port may be configured to provide fluid
communication between the sealed enclosure and the dressing. The
reduced-pressure port may include an inlet and an outlet configured
to provide fluid communication between the sealed enclosure and the
reduced-pressure source. The inlet may be configured to face the
sealed enclosure and the outlet may be configured to face the
reduced-pressure source. The fluid blockage device may be
configured to preclude fluid communication through the
reduced-pressure port when exposed to a liquid.
[0008] In some example embodiments, a canister assembly for
treating a tissue site with reduced-pressure may include a fluid
canister, a canister lid, a reduced-pressure port, and a fluid
blockage device. The fluid canister may have an internal volume
configured to receive fluid from the tissue site. The canister lid
may be configured to provide a sealed enclosure relative to the
fluid canister when the canister lid is sealingly engaged with the
fluid canister. The reduced-pressure port may include an inlet and
an outlet configured to provide fluid communication with the sealed
enclosure. The inlet may be configured to face the sealed enclosure
and the outlet may be configured to face outward from the sealed
enclosure. The fluid blockage device may be configured to preclude
fluid communication through the reduced-pressure port when exposed
to a liquid.
[0009] In some example embodiments, a fluid blockage device for
treating a tissue site with reduced pressure may include a carrier,
a primary filter, and an absorbent. The carrier may include a
fitting configured to be coupled in fluid communication with a
reduced-pressure source, and a flared opening in fluid
communication with the fitting. The primary filter may be
positioned at the flared opening of the carrier and configured to
be in fluid communication between the tissue site and the fitting.
The absorbent material may be in fluid communication between the
fitting and the primary filter. The absorbent material may be
configured to swell when exposed to a liquid.
[0010] In some example embodiments, a fluid blockage device for use
with a reduced-pressure source for treating a tissue site with
reduced pressure may include an absorbent material configured to be
positioned in fluid communication between the reduced-pressure
source and the tissue site. The absorbent material may be
configured to swell and to preclude fluid communication between the
reduced-pressure source and the tissue site when the absorbent
material is exposed to a liquid.
[0011] In some example embodiments, a fluid blockage device for use
with a reduced-pressure source for treating a tissue site with
reduced pressure may be configured to preclude fluid communication
through a port fluidly coupled to the reduced-pressure source when
the fluid blockage device contacts a liquid.
[0012] Objectives, advantages, and a preferred mode of making and
using the claimed subject matter may be understood best by
reference to the accompanying drawings in conjunction with the
following detailed description of illustrative example
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a block diagram of an example embodiment of a
therapy system suitable for providing negative-pressure treatment
and instillation treatment in accordance with this disclosure;
[0014] FIG. 2 is a perspective, exploded view of an example
embodiment of a canister assembly that may be associated with some
embodiments of the therapy system of FIG. 1;
[0015] FIG. 3 is a perspective, exploded view of an example
embodiment of a canister lid that may be associated with some
embodiments of the canister assembly of FIG. 2;
[0016] FIG. 4 is a perspective, exploded view of an example
embodiment of a fluid blockage device suitable for use with some
embodiments of the canister assembly or therapy system according to
this disclosure;
[0017] FIG. 5 is a perspective, exploded view of another example
embodiment of a fluid blockage device suitable for use with some
embodiments of the canister assembly or therapy system according to
this disclosure; and
[0018] FIG. 6 is a perspective, exploded view of another example
embodiment of a fluid blockage device suitable for use with some
embodiments of the canister assembly or therapy system according to
this disclosure.
DESCRIPTION OF EXAMPLE EMBODIMENTS
[0019] The following description discloses non-limiting,
illustrative example embodiments with sufficient detail to enable a
person skilled in the art to make and use the subject matter set
forth in the appended claims. Details that are well-known or not
necessary for the skilled person to make and use the claimed
subject matter may be omitted.
[0020] The example embodiments may also be described herein with
reference to spatial relationships between various elements or to
the spatial orientation of various elements depicted in the
attached drawings. In general, such relationships or orientation
assume a frame of reference consistent with or relative to a
patient in a position to receive treatment. However, as should be
recognized by those skilled in the art, this frame of reference is
merely a descriptive expedient rather than a strict
prescription.
[0021] FIG. 1 is a block diagram of an example embodiment of a
therapy system 100 that can provide negative-pressure therapy with
instillation of topical treatment solutions to a tissue site, such
as a tissue site 102, in accordance with this specification.
[0022] The term "tissue site" in this context broadly refers to a
wound, defect, or other treatment target located on or within
tissue, including, but not limited to, bone tissue, adipose tissue,
muscle tissue, neural tissue, dermal tissue, vascular tissue,
connective tissue, cartilage, tendons, or ligaments. A wound may
include chronic, acute, traumatic, subacute, and dehisced wounds,
partial-thickness burns, ulcers (such as diabetic, pressure, or
venous insufficiency ulcers), flaps, and grafts, for example. The
term "tissue site" may also refer to areas of any tissue that are
not necessarily wounded or defective, but are instead areas in
which it may be desirable to add or promote the growth of
additional tissue. For example, negative pressure may be applied to
a tissue site to grow additional tissue that may be harvested and
transplanted.
[0023] The therapy system 100 may include a source or supply of
negative pressure, such as a negative-pressure source 105, and one
or more distribution components. A distribution component is
preferably detachable and may be disposable, reusable, or
recyclable. A dressing, such as a dressing 110, and a fluid
container, such as a container 115, are examples of distribution
components that may be associated with some examples of the therapy
system 100. As illustrated in the example of FIG. 1, the dressing
110 may comprise or consist essentially of a tissue interface 120,
a cover 125, or both in some embodiments.
[0024] A fluid conductor is another illustrative example of a
distribution component. A "fluid conductor," in this context,
broadly includes a tube, pipe, hose, conduit, or other structure
with one or more lumina or open pathways adapted to convey a fluid
between two ends. Typically, a tube is an elongated, cylindrical
structure with some flexibility, but the geometry and rigidity may
vary. Moreover, some fluid conductors may be molded into or
otherwise integrally combined with other components. Distribution
components may also include or comprise interfaces or fluid ports
to facilitate coupling and de-coupling other components. In some
embodiments, for example, a dressing interface may facilitate
coupling a fluid conductor to the dressing 110. For example, such a
dressing interface may be a SENSAT.R.A.C..TM. Pad available from
Kinetic Concepts, Inc. of San Antonio, Tex.
[0025] The therapy system 100 may also include a regulator or
controller, such as a controller 130. Additionally, the therapy
system 100 may include sensors to measure operating parameters and
provide feedback signals to the controller 130 indicative of the
operating parameters. As illustrated in FIG. 1, for example, the
therapy system 100 may include a first sensor 135 and a second
sensor 140 coupled to the controller 130.
[0026] The therapy system 100 may also include a source of
instillation solution. For example, a solution source 145 may be
fluidly coupled to the dressing 110, as illustrated in the example
embodiment of FIG. 1. The solution source 145 may be fluidly
coupled to a positive-pressure source such as a positive-pressure
source 150, a negative-pressure source such as the
negative-pressure source 105, or both in some embodiments. A
regulator, such as an instillation regulator 155, may also be
fluidly coupled to the solution source 145 and the dressing 110 to
ensure proper dosage of instillation solution (e.g. saline) to a
tissue site. For example, the instillation regulator 155 may
comprise a piston that can be pneumatically actuated by the
negative-pressure source 105 to draw instillation solution from the
solution source during a negative-pressure interval and to instill
the solution to a dressing during a venting interval. Additionally
or alternatively, the controller 130 may be coupled to the
negative-pressure source 105, the positive-pressure source 150, or
both, to control dosage of instillation solution to a tissue site.
In some embodiments, the instillation regulator 155 may also be
fluidly coupled to the negative-pressure source 105 through the
dressing 110, as illustrated in the example of FIG. 1.
[0027] Some components of the therapy system 100 may be housed
within or used in conjunction with other components, such as
sensors, processing units, alarm indicators, memory, databases,
software, display devices, or user interfaces that further
facilitate therapy. For example, in some embodiments, the
negative-pressure source 105 may be combined with the controller
130, the solution source 145, and other components into a therapy
unit.
[0028] In general, components of the therapy system 100 may be
coupled directly or indirectly. For example, the negative-pressure
source 105 may be directly coupled to the container 115 and may be
indirectly coupled to the dressing 110 through the container 115.
Coupling may include fluid, mechanical, thermal, electrical, or
chemical coupling (such as a chemical bond), or some combination of
coupling in some contexts. For example, the negative-pressure
source 105 may be electrically coupled to the controller 130 and
may be fluidly coupled to one or more distribution components to
provide a fluid path to a tissue site. In some embodiments,
components may also be coupled by virtue of physical proximity,
being integral to a single structure, or being formed from the same
piece of material.
[0029] A negative-pressure supply, such as the negative-pressure
source 105, may be a reservoir of air at a negative pressure or may
be a manual or electrically-powered device, such as a vacuum pump,
a suction pump, a wall suction port available at many healthcare
facilities, or a micro-pump, for example. "Negative pressure"
generally refers to a pressure less than a local ambient pressure,
such as the ambient pressure in a local environment external to a
sealed therapeutic environment. In many cases, the local ambient
pressure may also be the atmospheric pressure at which a tissue
site is located. Alternatively, the pressure may be less than a
hydrostatic pressure associated with tissue at the tissue site.
Unless otherwise indicated, values of pressure stated herein are
gauge pressures. References to increases in negative pressure
typically refer to a decrease in absolute pressure, while decreases
in negative pressure typically refer to an increase in absolute
pressure. While the amount and nature of negative pressure provided
by the negative-pressure source 105 may vary according to
therapeutic requirements, the pressure is generally a low vacuum,
also commonly referred to as a rough vacuum, between -5 mm Hg (-667
Pa) and -500 mm Hg (-66.7 kPa). Common therapeutic ranges are
between -50 mm Hg (-6.7 kPa) and -300 mm Hg (-39.9 kPa).
[0030] The container 115 is representative of a container,
canister, pouch, or other storage component, which can be used to
manage exudates and other fluids withdrawn from a tissue site. In
many environments, a rigid container may be preferred or required
for collecting, storing, and disposing of fluids. In other
environments, fluids may be properly disposed of without rigid
container storage, and a re-usable container could reduce waste and
costs associated with negative-pressure therapy.
[0031] A controller, such as the controller 130, may be a
microprocessor or computer programmed to operate one or more
components of the therapy system 100, such as the negative-pressure
source 105. In some embodiments, for example, the controller 130
may be a microcontroller, which generally comprises an integrated
circuit containing a processor core and a memory programmed to
directly or indirectly control one or more operating parameters of
the therapy system 100. Operating parameters may include the power
applied to the negative-pressure source 105, the pressure generated
by the negative-pressure source 105, or the pressure distributed to
the tissue interface 120, for example. The controller 130 is also
preferably configured to receive one or more input signals, such as
a feedback signal, and programmed to modify one or more operating
parameters based on the input signals.
[0032] Sensors, such as the first sensor 135 and the second sensor
140, are generally known in the art as any apparatus operable to
detect or measure a physical phenomenon or property, and generally
provide a signal indicative of the phenomenon or property that is
detected or measured. For example, the first sensor 135 and the
second sensor 140 may be configured to measure one or more
operating parameters of the therapy system 100. In some
embodiments, the first sensor 135 may be a transducer configured to
measure pressure in a pneumatic pathway and convert the measurement
to a signal indicative of the pressure measured. In some
embodiments, for example, the first sensor 135 may be a
piezo-resistive strain gauge. The second sensor 140 may optionally
measure operating parameters of the negative-pressure source 105,
such as a voltage or current, in some embodiments. Preferably, the
signals from the first sensor 135 and the second sensor 140 are
suitable as an input signal to the controller 130, but some signal
conditioning may be appropriate in some embodiments. For example,
the signal may need to be filtered or amplified before it can be
processed by the controller 130. Typically, the signal is an
electrical signal, but may be represented in other forms, such as
an optical signal.
[0033] The tissue interface 120 can be generally adapted to
partially or fully contact a tissue site. The tissue interface 120
may take many forms, and may have many sizes, shapes, or
thicknesses, depending on a variety of factors, such as the type of
treatment being implemented or the nature and size of a tissue
site. For example, the size and shape of the tissue interface 120
may be adapted to the contours of deep and irregular shaped tissue
sites. Any or all of the surfaces of the tissue interface 120 may
have an uneven, coarse, or jagged profile.
[0034] In some embodiments, the tissue interface 120 may comprise
or consist essentially of a manifold. A manifold in this context
may comprise or consist essentially of a means for collecting or
distributing fluid across the tissue interface 120 under pressure.
For example, a manifold may be adapted to receive negative pressure
from a source and distribute negative pressure through multiple
apertures across the tissue interface 120, which may have the
effect of collecting fluid from across a tissue site and drawing
the fluid toward the source. In some embodiments, the fluid path
may be reversed or a secondary fluid path may be provided to
facilitate delivering fluid, such as fluid from a source of
instillation solution, across a tissue site.
[0035] In some illustrative embodiments, a manifold may comprise a
plurality of pathways, which can be interconnected to improve
distribution or collection of fluids. In some illustrative
embodiments, a manifold may comprise or consist essentially of a
porous material having interconnected fluid pathways. Examples of
suitable porous material that can be adapted to form interconnected
fluid pathways (e.g., channels) may include cellular foam,
including open-cell foam such as reticulated foam; porous tissue
collections; and other porous material such as gauze or felted mat
that generally include pores, edges, and/or walls. Liquids, gels,
and other foams may also include or be cured to include apertures
and fluid pathways. In some embodiments, a manifold may
additionally or alternatively comprise projections that form
interconnected fluid pathways. For example, a manifold may be
molded to provide surface projections that define interconnected
fluid pathways.
[0036] In some embodiments, the tissue interface 120 may comprise
or consist essentially of reticulated foam having pore sizes and
free volume that may vary according to needs of a prescribed
therapy. For example, reticulated foam having a free volume of at
least 90% may be suitable for many therapy applications, and foam
having an average pore size in a range of 400-600 microns (40-50
pores per inch) may be particularly suitable for some types of
therapy. The tensile strength of the tissue interface 120 may also
vary according to needs of a prescribed therapy. For example, the
tensile strength of foam may be increased for instillation of
topical treatment solutions. The 25% compression load deflection of
the tissue interface 120 may be at least 0.35 pounds per square
inch, and the 65% compression load deflection may be at least 0.43
pounds per square inch. In some embodiments, the tensile strength
of the tissue interface 120 may be at least 10 pounds per square
inch. The tissue interface 120 may have a tear strength of at least
2.5 pounds per inch. In some embodiments, the tissue interface may
be foam comprised of polyols such as polyester or polyether,
isocyanate such as toluene diisocyanate, and polymerization
modifiers such as amines and tin compounds. In some examples, the
tissue interface 120 may be reticulated polyurethane foam such as
found in GRANUFOAM.TM. dressing or V.A.C. VERAFLO.TM. dressing,
both available from Kinetic Concepts, Inc. of San Antonio, Tex.
[0037] The thickness of the tissue interface 120 may also vary
according to needs of a prescribed therapy. For example, the
thickness of the tissue interface may be decreased to reduce
tension on peripheral tissue. The thickness of the tissue interface
120 can also affect the conformability of the tissue interface 120.
In some embodiments, a thickness in a range of about 5 millimeters
to 10 millimeters may be suitable.
[0038] The tissue interface 120 may be either hydrophobic or
hydrophilic. In an example in which the tissue interface 120 may be
hydrophilic, the tissue interface 120 may also wick fluid away from
a tissue site, while continuing to distribute negative pressure to
the tissue site. The wicking properties of the tissue interface 120
may draw fluid away from a tissue site by capillary flow or other
wicking mechanisms. An example of a hydrophilic material that may
be suitable is a polyvinyl alcohol, open-cell foam such as V.A.C.
WHITEFOAM.TM. dressing available from Kinetic Concepts, Inc. of San
Antonio, Tex. Other hydrophilic foams may include those made from
polyether. Other foams that may exhibit hydrophilic characteristics
include hydrophobic foams that have been treated or coated to
provide hydrophilicity.
[0039] In some embodiments, the tissue interface 120 may be
constructed from bioresorbable materials. Suitable bioresorbable
materials may include, without limitation, a polymeric blend of
polylactic acid (PLA) and polyglycolic acid (PGA). The polymeric
blend may also include, without limitation, polycarbonates,
polyfumarates, and capralactones. The tissue interface 120 may
further serve as a scaffold for new cell-growth, or a scaffold
material may be used in conjunction with the tissue interface 120
to promote cell-growth. A scaffold is generally a substance or
structure used to enhance or promote the growth of cells or
formation of tissue, such as a three-dimensional porous structure
that provides a template for cell growth. Illustrative examples of
scaffold materials include calcium phosphate, collagen, PLA/PGA,
coral hydroxy apatites, carbonates, or processed allograft
materials.
[0040] In some embodiments, the cover 125 may provide a bacterial
barrier and protection from physical trauma. The cover 125 may also
be constructed from a material that can reduce evaporative losses
and provide a fluid seal between two components or two
environments, such as between a therapeutic environment and a local
external environment. The cover 125 may comprise or consist of, for
example, an elastomeric film or membrane that can provide a seal
adequate to maintain a negative pressure at a tissue site for a
given negative-pressure source. The cover 125 may have a high
moisture-vapor transmission rate (MVTR) in some applications. For
example, the MVTR may be at least 250 grams per square meter per
twenty-four hours in some embodiments, measured using an upright
cup technique according to ASTM E96/E96M Upright Cup Method at
38.degree. C. and 10% relative humidity (RH). In some embodiments,
an MVTR up to 5,000 grams per square meter per twenty-four hours
may provide effective breathability and mechanical properties.
[0041] In some example embodiments, the cover 125 may be a polymer
drape, such as a polyurethane film, that is permeable to water
vapor but impermeable to liquid. Such drapes typically have a
thickness in the range of 25-50 microns. For permeable materials,
the permeability generally should be low enough that a desired
negative pressure may be maintained. The cover 125 may comprise,
for example, one or more of the following materials: polyurethane
(PU), such as hydrophilic polyurethane; cellulosics; hydrophilic
polyamides; polyvinyl alcohol; polyvinyl pyrrolidone; hydrophilic
acrylics; silicones, such as hydrophilic silicone elastomers;
natural rubbers; polyisoprene; styrene butadiene rubber;
chloroprene rubber; polybutadiene; nitrile rubber; butyl rubber;
ethylene propylene rubber; ethylene propylene diene monomer;
chlorosulfonated polyethylene; polysulfide rubber; ethylene vinyl
acetate (EVA); co-polyester; and polyether block polymide
copolymers. Such materials are commercially available as, for
example, Tegaderm.RTM. drape, commercially available from 3M
Company, Minneapolis Minn.; polyurethane (PU) drape, commercially
available from Avery Dennison Corporation, Pasadena, Calif.;
polyether block polyamide copolymer (PEBAX), for example, from
Arkema S.A., Colombes, France; and Inspire 2301 and Inpsire 2327
polyurethane films, commercially available from Expopack Advanced
Coatings, Wrexham, United Kingdom. In some embodiments, the cover
125 may comprise INSPIRE 2301 having an MVTR (upright cup
technique) of 2600 g/m.sup.2/24 hours and a thickness of about 30
microns.
[0042] An attachment device may be used to attach the cover 125 to
an attachment surface, such as undamaged epidermis, a gasket, or
another cover. The attachment device may take many forms. For
example, an attachment device may be a medically-acceptable,
pressure-sensitive adhesive configured to bond the cover 125 to
epidermis around a tissue site. In some embodiments, for example,
some or all of the cover 125 may be coated with an adhesive, such
as an acrylic adhesive, which may have a coating weight of about
25-65 grams per square meter (g.s.m.). Thicker adhesives, or
combinations of adhesives, may be applied in some embodiments to
improve the seal and reduce leaks. Other example embodiments of an
attachment device may include a double-sided tape, paste,
hydrocolloid, hydrogel, silicone gel, or organogel.
[0043] The solution source 145 may also be representative of a
container, canister, pouch, bag, or other storage component, which
can provide a solution for instillation therapy. Compositions of
solutions may vary according to a prescribed therapy, but examples
of solutions that may be suitable for some prescriptions include
hypochlorite-based solutions, silver nitrate (0.5%), sulfur-based
solutions, biguanides, cationic solutions, and isotonic
solutions.
[0044] In operation, the tissue interface 120 may be placed within,
over, on, or otherwise proximate to a tissue site. If the tissue
site is a wound, for example, the tissue interface 120 may
partially or completely fill the wound, or it may be placed over
the wound. The cover 125 may be placed over the tissue interface
120 and sealed to an attachment surface near a tissue site. For
example, the cover 125 may be sealed to undamaged epidermis
peripheral to a tissue site. Thus, the dressing 110 can provide a
sealed therapeutic environment proximate to a tissue site,
substantially isolated from the external environment, and the
negative-pressure source 105 can reduce pressure in the sealed
therapeutic environment.
[0045] The process of reducing pressure may be described
illustratively herein as "delivering," "distributing," or
"generating" negative pressure, for example. In general, exudate
and other fluid flow toward lower pressure along a fluid path.
Thus, the term "downstream" may refer to a location in a fluid path
relatively closer to a source of negative pressure or further away
from a source of positive pressure. Conversely, the term "upstream"
may refer to a location further away from a source of negative
pressure or closer to a source of positive pressure.
[0046] Negative pressure applied across the tissue site through the
tissue interface 120 in the sealed therapeutic environment can
induce macro-strain and micro-strain in the tissue site. Negative
pressure can also remove exudate and other fluid from a tissue
site, which can be collected in container 115.
[0047] In some embodiments, the controller 130 may receive and
process data from one or more sensors, such as the first sensor
135. The controller 130 may also control the operation of one or
more components of the therapy system 100 to manage the pressure
delivered to the tissue interface 120. In some embodiments,
controller 130 may include an input for receiving a desired target
pressure and may be programmed for processing data relating to the
setting and inputting of the target pressure to be applied to the
tissue interface 120. In some example embodiments, the target
pressure may be a fixed pressure value set by an operator as the
target negative pressure desired for therapy at a tissue site and
then provided as input to the controller 130. The target pressure
may vary from tissue site to tissue site based on the type of
tissue forming a tissue site, the type of injury or wound (if any),
the medical condition of the patient, and the preference of the
attending physician. After selecting a desired target pressure, the
controller 130 can operate the negative-pressure source 105 in one
or more control modes based on the target pressure and may receive
feedback from one or more sensors to maintain the target pressure
at the tissue interface 120.
[0048] Further, in some embodiments, the controller 130 may receive
and process data, such as data related to instillation solution
provided to the tissue interface 120. Such data may include the
type of instillation solution prescribed by a clinician, the volume
of fluid or solution to be instilled to a tissue site ("fill
volume"), and the amount of time prescribed for leaving solution at
a tissue site ("dwell time") before applying a negative pressure to
the tissue site. The fill volume may be, for example, between 10
and 500 mL, and the dwell time may be between one second to 30
minutes. The controller 130 may also control the operation of one
or more components of the therapy system 100 to instill solution.
For example, the controller 130 may manage fluid distributed from
the solution source 145 to the tissue interface 120. In some
embodiments, fluid may be instilled to a tissue site by applying a
negative pressure from the negative-pressure source 105 to reduce
the pressure at the tissue site, drawing solution into the tissue
interface 120. In some embodiments, solution may be instilled to a
tissue site by applying a positive pressure from the
positive-pressure source 160 to move solution from the solution
source 145 to the tissue interface 120. Additionally or
alternatively, the solution source 145 may be elevated to a height
sufficient to allow gravity to move solution into the tissue
interface 120.
[0049] Referring to FIGS. 1-2, in some example embodiments, the
therapy system 100 may include the dressing 110, the
negative-pressure source 105, and the container 115. The dressing
110 may be configured to be positioned in contact with the tissue
site 102. The negative-pressure source 105 may be referred to as a
reduced-pressure source 105 and may be configured to be in fluid
communication with the dressing 110. The container 115 may be an
assembly, in part or in whole, and may be referred to as a canister
assembly 115. The dressing 110 may be configured to distribute a
reduced pressure to the tissue site 102 that is communicated from
the reduced-pressure source 105 through the canister assembly
115.
[0050] Referring to FIGS. 1-4, in some embodiments, the canister
assembly 115 may include a fluid canister 200, a canister lid 202,
a fluid entry port 204, a reduced-pressure port 206, and a fluid
blockage device 208. One or more elements of the canister assembly
115 may be removed or additional elements may be added as described
herein depending on therapeutic requirements or preferences.
[0051] The canister assembly 115 may be configured to be positioned
in fluid communication between the dressing 110 and the
reduced-pressure source 105. For example, the reduced-pressure
source 105 may be configured to be coupled in fluid communication
with the reduced-pressure port 206, and the dressing 110 may be
configured to be coupled in fluid communication with the fluid
entry port 204 of the canister assembly 115. The fluid entry port
204 may be in fluid communication with the reduced-pressure port
206 through the sealed enclosure 214 of the canister assembly 115
such that the reduced-pressure source 105 is coupled in fluid
communication with the dressing 110 and the tissue site 102 through
the sealed enclosure 214.
[0052] The fluid canister 200 may have an internal volume 210
configured to receive fluid, such as fluid from the tissue site
102. The canister lid 202 may be configured to provide a sealed
enclosure 214 relative to or in combination with the fluid canister
200 when the canister lid 202 is sealingly engaged with the fluid
canister 200. In some embodiments, the canister lid 202 may be
permanently sealed to the fluid canister 200. The fluid entry port
204 may be configured to provide fluid communication between the
sealed enclosure 214 and the dressing 110.
[0053] The reduced-pressure port 206 may include an inlet 216 and
an outlet 218 configured to provide fluid communication between the
sealed enclosure 214 and the reduced-pressure source 105. The inlet
216 may be configured to face the sealed enclosure 214 and the
outlet 218 may be configured to face the reduced-pressure source
105 or to face outward from the sealed enclosure 214. The fluid
blockage device 208 may be positioned at or between the inlet 216
and the outlet 216 of the reduced-pressure port 206. Further, the
fluid blockage device 208 may be configured to preclude fluid
communication through the reduced-pressure port 206 when exposed to
a liquid as described further herein.
[0054] In some examples, the therapy system 100 may include a
pressure feedback port 220 configured to be in fluid communication
with the sealed enclosure 214 and to provide a pressure signal
corresponding to a pressure in the sealed enclosure 214. The
pressure feedback port 220 may be configured to provide a pressure
feedback signal to the controller 130 directly or through a
pressure sensor, such as the first sensor 135. In some examples,
the canister lid 202 may carry the fluid entry port 204, the
pressure feedback port 220, and the reduced-pressure port 206. In
some examples, the fluid entry port 204, the pressure feedback port
220, and the reduced-pressure port 206 may be fluidly disposed
through the canister lid 202.
[0055] Further, in some examples, the therapy system 100 may
include a primary filter 222 configured to be in fluid
communication between the sealed enclosure 214 and the
reduced-pressure source 105. The primary filter 222 may be
hydrophobic and may include a sintered, hydrophobic polymer having
various sizes, shapes, and configurations as shown in FIGS. 2-6,
for example. The primary filter 222 may be directly exposed to the
internal volume 210 of the fluid canister 200 and any liquid
present in the sealed enclosure 214 during operation. The
reduced-pressure port 206 may carry the primary filter 222
proximate to or at the inlet 216 of the reduced-pressure port 206.
In some examples, the primary filter 222 may be sized to fit around
an external diameter 223 of the reduced-pressure port 206 as shown
in FIGS. 2-5.
[0056] FIGS. 4-6 depict various non-limiting example embodiments of
the fluid blockage device 208. The fluid blockage device 208 may be
configured to be positioned between the reduced-pressure source 105
and the tissue site 102. For example, the fluid blockage device 208
may be configured to be positioned in fluid communication between
the outlet 218 of the reduced-pressure port 206 and the sealed
enclosure 214, shown in FIG. 2. The fluid blockage device 208 may
be operable to block or preclude fluid communication between the
reduced-pressure source 105 and the tissue site 102 when certain
operating conditions are encountered. For example, the fluid
blockage device 208 may block fluid communication through the
reduced-pressure port 206 to the reduced-pressure source 105, for
example, when a level of liquid in the fluid canister 200 reaches
the inlet 216 of the reduced-pressure port 206, when liquid
splashes or overly saturates the primary filter 222, or the primary
filter 222 experiences a failure. Such a configuration may trigger
a system shut down alarm to protect components of the therapy
system 100 from contamination or liquid exposure, such as the
reduced-pressure source 105, electronic components, or other
components that may be sensitive to liquid or bacterial exposure.
The fluid blockage device 208 may also include, operate as, or be
referred to as a secondary filter 208.
[0057] Referring to FIG. 4, in some examples, the fluid blockage
device 208 may be a fluid blockage device 208a. The fluid blockage
device 208a may be configured to be positioned in fluid
communication between the primary filter 222 and the
reduced-pressure source 105. In some examples, the fluid blockage
device 208a may be positioned in fluid communication between the
primary filter 222 and the outlet 218 of the reduced-pressure port
206. The fluid blockage device 208a may include or be formed of an
absorbent material configured to swell when exposed to liquid. For
example, the fluid blockage device 208a may include or be formed of
a sintered, super absorbent polymer. Further, in some examples, the
fluid blockage device 208a may include or be formed of a super
absorbent polymer and charcoal.
[0058] In some examples, the fluid blockage device 208a may include
or be formed as a tube 225 having an external diameter 226 sized to
fit within and to engage an internal diameter 228 of the
reduced-pressure port 206 between the inlet 216 and the outlet 218.
The tube 225 may include an internal lumen 230 extending through
opposing ends of the tube 225. The tube 225 may be configured to
swell when in direct contact with a liquid such that the internal
lumen 230 is blocked or occluded and the external diameter 226 of
the tube 225 sealingly engages the internal diameter 228 of the
reduced-pressure port 206, creating a blockage in the
reduced-pressure port 206. In some examples, the internal lumen 230
of the tube 225 may have an internal diameter 232 between about 3.5
millimeters to about 7.2 millimeters. Further, in some examples,
the tube 225 may have a length 234 between about 22 millimeters to
about 26 millimeters. In some examples, the tube 225 of the fluid
blockage device 208a may include or be formed of a molded slug of
absorbent carboxymethyl cellulose granules, such as LUQUASORB.RTM.,
available from BASF of Florham Park, N.J., USA.
[0059] In some examples, a filter membrane 224 may be positioned
between the outlet 218 of the reduced-pressure port 206 and the
fluid blockage device 208a and configured to retain the fluid
blockage device 208a within the canister assembly 115 or the
canister lid 202. In some examples, the filter membrane 224 may
include or be formed of one or more of the following materials: a
non-woven material and a cellulose material. In some examples, the
filter membrane 224 may include or be formed of LIBELTEX TDL2 or
LIBELTEX TL4 and may have a material density between about 80 gsm
to about 150 gsm.
[0060] Referring to FIG. 5, in some examples, the fluid blockage
device 208 may be a fluid blockage device 208b. The fluid blockage
device 208b may include a protective housing 236. The protective
housing 236 may include a base 238, a fluid aperture 240 disposed
through the base 238, a side-wall 242 extending outward from and
around the base 238 to form a chamber 244, and a chamber opening
246 sized to receive the reduced-pressure port 206 and the primary
filter 222 within the chamber 244. The fluid aperture 240 may be
disposed through the base 238 of the protective housing 236. In
some examples, the base 238 having the fluid aperture 240 may be a
component of the protective housing 236 having a maximum distance
of extension from the reduced-pressure port 206 into the sealed
enclosure 214. In some examples (not shown), the fluid aperture 240
may be biased toward the side-wall 242 of the protective housing
236, which may position the fluid aperture 240 in a substantially
central location underneath the canister lid 202.
[0061] The fluid aperture 240 may be configured to provide fluid
communication between the reduced-pressure port 206 and the sealed
enclosure 214 until a liquid level in the sealed enclosure 214
reaches the fluid aperture 240 and blocks or occludes the fluid
aperture 240. The protective housing 236 may be configured to
surround and to cover the reduced-pressure port 206. In some
examples, the fluid aperture 240 is configured to provide all fluid
communication between the reduced-pressure port 206 and the sealed
enclosure 214 such that a blockage of the fluid aperture 240 causes
an entire blockage of all fluid communication between the
reduced-pressure source 105 and the tissue site 102. In some
examples, the fluid aperture 240 may have a diameter 248 between
about 3 millimeters to about 5 millimeters. Shown as an
illustrative example in FIG. 5, the protective housing 236 may be
coupled around the inlet 216 of the reduced-pressure port 206 with
an interference or compression fit. The protective housing 236 may
comprise, be formed of, or molded from any stable polymer material,
such as, without limitation, polyethylene (PE) or acrylonitrile
butadiene styrene (ABS).
[0062] Referring to FIG. 6, in some examples, the therapy system
100 may include a carrier 250 and the fluid blockage device 208 may
be a fluid blockage device 208c. The fluid blockage device 208c may
be used with the carrier 250 as part of the therapy system 100, or
the carrier 250 may form part of the fluid blockage device 208c.
The fluid blockage device 208c may be configured to be positioned
in fluid communication between the primary filter 222 and the
reduced-pressure source 105. Further, in some examples, the fluid
blockage device 208c may be positioned in fluid communication
between the primary filter 222 and the outlet 218 of the
reduced-pressure port 206. As shown in FIG. 6, the primary filter
222 may have, without limitation, a circular or disc-like shape.
Although shown as having a different shape, the primary filter 222
shown in FIG. 6 may be comprised of similar or analogous materials
as the previously described examples of the primary filter 222.
[0063] The carrier 250 may include a fitting, such as a
reduced-pressure port fitting 252, and a flared opening 254. The
fitting or the reduced-pressure port fitting 252 may be configured
to be coupled in fluid communication with the reduced-pressure
source 105 through the reduced-pressure port 206, for example. The
flared opening 254 may be in fluid communication with the fitting
or the reduced-pressure port fitting 252 through the carrier 250.
The flared opening 254 may have a flared diameter 256 larger than a
fitting diameter 258 of the reduced-pressure port fitting 252. The
fitting diameter 258 of the reduced-pressure port fitting 252 may
be sized to fit over or around the external diameter 223 of the
reduced-pressure port 206 to provide fluid communication between
the reduced-pressure port 206 and the carrier 250. In some
examples, the flared diameter 256 of the flared opening 254 may be
substantially the same as an internal diameter 260 of the fluid
canister 200, shown in FIG. 2, which may provide additional
filtration surface area for preventing clogs or obstructions.
[0064] The primary filter 222 may be positioned at the flared
opening 254 of the carrier 250. The primary filter 222 may be
configured to be positioned in fluid communication between the
tissue site 102 and the fitting or the reduced-pressure port
fitting 252. For example, the primary filter 222 may be configured
to be positioned in fluid communication between the sealed
enclosure 214 and the fitting or the reduced-pressure port fitting
252. The fluid blockage device 208c may be configured to be
positioned in fluid communication between the fitting or the
reduced-pressure port fitting 252 and the primary filter 222. The
fluid blockage device 208c may include or be formed of an absorbent
material configured to swell when exposed to a liquid and to block
fluid communication to the reduced-pressure source 105 through the
reduced-pressure port. For example, the fluid blockage device 208c
may include or be formed of a sintered, super absorbent polymer.
Further, the fluid blockage device 208c may include or be formed of
a super absorbent polymer and charcoal. Although the fluid blockage
device 208c is shown in FIG. 6 as a cylindrical device sized for
the reduced-pressure port 206, in other examples, the fluid
blockage device 208c may fit within the carrier 250 and may take
the form of a granules.
[0065] While shown in a few illustrative embodiments, a person
having ordinary skill in the art will recognize that the systems,
apparatuses, and methods described herein are susceptible to
various changes and modifications that fall within the scope of the
appended claims. Moreover, descriptions of various alternatives
using terms such as "or" do not require mutual exclusivity unless
clearly required by the context, and the indefinite articles "a" or
"an" do not limit the subject to a single instance unless clearly
required by the context. Components may be also be combined or
eliminated in various configurations for purposes of sale,
manufacture, assembly, or use. For example, in some configurations
the dressing 110, the container 115, or both may be eliminated or
separated from other components for manufacture or sale. In other
example configurations, the controller 130 may also be
manufactured, configured, assembled, or sold independently of other
components.
[0066] The appended claims set forth novel and inventive aspects of
the subject matter described above, but the claims may also
encompass additional subject matter not specifically recited in
detail. For example, certain features, elements, or aspects may be
omitted from the claims if not necessary to distinguish the novel
and inventive features from what is already known to a person
having ordinary skill in the art. Features, elements, and aspects
described in the context of some embodiments may also be omitted,
combined, or replaced by alternative features serving the same,
equivalent, or similar purpose without departing from the scope of
the invention defined by the appended claims.
* * * * *